Liquid hydrocarbon or bioethanol heating appliance

ABSTRACT

A liquid hydrocarbon or bioethanol heating appliance ( 10 ), typically and non critically shaped as a movable fireplace with parallelepiped configuration, comprises a base ( 16 ), opposite side bands ( 12 ) with vertical development and a top connection panel ( 14 ) extended crosswise. The base is provided with an opening ( 20 ) on the exposed top front, which can be screened with movable separators ( 32 ) and incorporates a tank ( 22 ) and a combustion chamber or burner ( 24 ) connected to the tank by a conduit ( 26 ). The appliance comprises a valve or solenoid valve ( 30 ) or ( 42 ) provided with or combined to means that detect the fuel level in the burner ( 24 ) and temporarily activate the same valves for allowing the passage of the amount of fuel required for restoring a given level in said burner.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of Italian application No. MI2011A000156 filed Feb. 4, 2011 the disclosure of which is incorporated by reference.

DESCRIPTION

The present invention relates to a liquid hydrocarbon or bioethanol heating appliance.

More in particular, the present invention relates to a heating appliance shaped as a fireplace for household environments and in general but not exclusively, for interiors, apt to be variably positioned in various zones of the rooms as it does not require the connection to a flue for conveying the combustion gases outwards.

Heating appliances of this kind, wherein the combustion of bioethanol or of an optional similar fuel such as kerosene occurs at the air-vapour mixture state of the same fuel, have long been known; since the combustion of a minimum amount of bioethanol produces very low levels of toxic gases, such appliances may be easily used in closed rooms and without flues for a given number of hours, although aerating the room is recommended. In addition to the heating effect, the same appliances also represent furnishing elements with ornamental features of a various nature. For safety purposes, with special reference to the fire hazard of the fuel contained within the appliance tank, as well as with reference to the accidental overturning of the entire structure that is not secured to the floor, the known subject heating appliances have been provided with devices apt to prevent the entire amount of fuel equal to the tank capacity to be arranged within the burner.

A first embodiment of bioethanol appliances, in fact, provided for the entire amount of fuel required for the expected operating hours to be arranged within the burner, so that the flame burnt by combustion of the mixture of air-vapour, the latter floating on the whole flammable liquid. In this case, a collision or the violent movement of the fireplace as well as the accidental overturning thereof, caused the fuel overflow with the very likely risk of a fire. Subsequent embodiments of bioethanol appliances or fireplaces led to separate the tank from the burner; in the latter, the amount of fuel is small whereas the tank located away from the burner contains most of the flammable liquid.

The feeding is carried out by pressure difference between closed tank and atmospheric pressure; in particular, when the combustion decreases the liquid level within the burner bringing it below the feeding hole, some air bubbles enter into the tank, altering the pressure balance, until the liquid flows from the tank into the burner and restores the original level.

However, also this solution does not offer full safety guarantees against the occurrence of possible fires, since the tank liquid always communicates with the combustion chamber; since the liquid level within the tank is very high compared to the burner, in the event of a failure of the levelling system the liquid present into the tank may spill out of the combustion chamber and propagate onto the floor. This may happen, for example, due to a transfer of air into the tank, with considerably serious consequences.

A further drawback of the known subject heating appliances wherein tank and burner are separate relates to the loading of fuel into the tank.

A first solution provides for a removable tank, which however exhibits the drawback of a possible damage of the coupling components the same tank is provided with during the movement that takes place during the fuel loading step.

The same tank may be damaged during such operation, with the risk of progressively leaking the liquid once placed and left unattended.

According to another known solution, the tank is attached to the heating appliance. In this case, the filling is often difficult and the tank placement is anything but optimal since it is close to the burner. Moreover, fixed tanks are provided with a gravity filling hole, with the consequence that the hazardous spilling of the liquid fuel in the filling step is highly likely.

A further drawback found in the known subject heating appliances relates to the fuel dispensing to the burner; such dispensing, in fact, is usually based on pressure balances and conduit sizes that may easily alter under certain conditions, such as for example if the appliance is moved or arranged on a surface that is not perfectly flat.

A bioethanol heating fireplace is known from Fr 2 927 149, wherein the fuel tank is arranged away from the burner zone for safety reasons; therefore, close to the flame there is a minimum amount of fuel, fed by a pump. However, this solution exhibits several drawbacks, for example related to the fact that the fuel within the tank heats and develops flammable vapours that could propagate despite the provision of a siphon device, especially suitable for the liquid. Moreover, this solution does not provide for safety systems apt to prevent accidental spilling of the fuel in the event of collisions and/or sudden movements. The risk resulting from a possible failure of the level detectors should also be contemplated, as it may lead the pump to feed the entire fuel of the tank into the combustion chamber. This would cause the hazardous overflow of a considerable part of the fuel outside, considering that the volume of the latter is significantly larger than the capacity of the combustion chamber.

A similar bioethanol heating appliance is also known from Fr 2 931 538, which exhibits the same considerable drawback related to the possible failure of the fuel level detectors.

Another drawback, also found in the solution of the above French patent as well, relates to the fuel filling system; even in the presence of a gate apt to lock the operation of the pump that fills the burner with fuel, there are no means that prevent the fuel from being directly poured into the burner when the appliance is switched off. This implies considerable hazards since the burner and the surroundings thereof may still be very hot even though the appliance has previously been switched off.

The object of the present invention is to obviate the drawbacks mentioned hereinabove.

More in particular, the object of the present invention is to provide a liquid hydrocarbon or bioethanol heating appliance wherein the flammable liquid present into the tank is suitably and constantly isolated from the combustion chamber, except during the feeding steps when the appliance is actually switched on.

A further object of the invention is to provide an appliance as defined above wherein the fuel tank filling is carried out easily and under totally safe conditions.

A further object of the invention is to provide a bioethanol heating appliance wherein the operation of direct filling of the fuel into the tank is prevented when the appliance is switched off.

Last but not least, an object of the invention is to provide a heating appliance wherein the dispensing of the fuel required for feeding the burner takes place with very high accuracy and safe from hazards of any kind.

A further object of the invention is to provide the users with a heating appliance apt to ensure a high level of resistance and reliability over time, also such as to be easily and inexpensively constructed.

These and yet other objects are achieved by the liquid hydrocarbon or bioethanol heating appliance of the present invention according to the main claim.

The construction and functional features of the heating appliance of the present invention shall be better understood from the following drawing tables showing a preferred and non-limiting embodiment thereof, and wherein:

FIG. 1 schematically shows a perspective front view of the heating appliance of the present invention;

FIGS. 2 and 3 schematically show the essential components of the same appliance and the respective connections under two different conditions;

FIG. 4 schematically shows a front partly cutaway view of the device for adjusting the fuel level present within the heating appliance;

FIG. 5 schematically shows a perspective view of the assembly consisting of the tank and the combustion chamber, by way of an example closed by top separators of the same heating appliance;

FIG. 6 schematically shows a perspective view of the same assembly of FIG. 5 wherein, however, the separators of the combustion chamber are open;

FIG. 7 schematically shows a perspective view of the same assembly of the previous figures with the combustion chamber cutaway crosswise to highlight an underlying cavity for collecting the fuel in the event of an emergency;

FIG. 8 schematically shows a perspective view of the heating appliance of the present invention, highlighting the possibility of replacing the structure covering panels.

With initial reference to FIG. 1, the heating appliance of the present invention is advantageously made in the shape of a fireplace, globally indicated with reference numeral 10, consisting of a regular parallelepiped structure with rectangular plan.

Said structure is defined by two opposite side bands 12 with vertical development, connected to each other at the top by a crosswise panel 14 and delimiting a base 16 at the bottom which incorporates the combustion chamber, the fuel tank and the functional components that shall be described hereinafter.

The area delimited by bands 12, by the crosswise panel 14 and by base 16 is partly screened, on opposite front and back fronts, by respective sheets 18 of a transparent material such as glass, crystal or the like.

The exposed top front of base 16 is centrally provided with an opening 20, preferably having a rectangular shape, wherein the longer sides extend parallel to the front and back edges of the same base; opening 20 defines the combustion chamber mouth wherefrom the flame develops and which may be closed by one or more separators, described hereinafter.

As schematically shown in FIGS. 2 and 3, the bioethanol fireplace or heating appliance 10 comprises a set of structural and functional components that are integrated within base 16. In particular, within base 16 there are seated a metal tank 22, a combustion chamber 24 connected to the same tank by a conduit 26 wherealong a safety valve 30 and a valve 28 for intercepting and levelling the combustible liquid within the combustion chamber 24. Said latter consists of a metal container, of any shape and size compatible with the amount of fuel contained within tank 22, at the top whereof there is defined said opening 20 wherefrom the flame indicated with “F” comes out.

Opening 20 may be screened by means of opposite separators 32, the larger or smaller opening whereof causes a corresponding heating effect. Separators 32 are kept closed, that is, in a reciprocal approach that screens the combustion chamber 24, by helical springs 34, whereas they are activated to open up or reciprocally separate by means of an electrical motor 36, for example of the magnetic stepping type, cooperating with a rod 37 coupled to racks 39. During the appliance operation, that is, with flame on, the electrical motor 36 is always tensioned to keep separators 32 open; otherwise, the helical springs 34 compress up to automatically return packet-wise and close separators 32 causing the switching off of flame “F” by choking, that is, lack of combustible.

In order to keep a low but sufficient and constant level of fuel within the combustion chamber 24, to minimise the hazards resulting from an accidental spilling, it is contemplated that valve 30 automatically opens and closes upon reaching predefined minimum and maximum levels of the same fuel within said chamber. The level detection is for example carried out by one or more probes 38 preferably arranged into the safety valve 28, or by a magnet detector or by one or more metal electrodes seated within the combustion chamber 24, as per page 7; the consequent activation of valve 30, which allows the liquid passage from tank 22 to the combustion chamber 24 for restoring the level established within the same chamber is advantageously managed by an electronic control unit 40 supplied by a rechargeable battery. Besides the advantage of keeping a low fuel level within the combustion chamber 24, this solution allows keeping valve 30 mainly closed; in fact, it opens up for a few seconds only, required to restore the contemplated liquid level within the combustion chamber 24, causing both a considerable reduction of the battery energy consumption and a significant increase in the overall safety, as it keeps tank 22 normally separated from said combustion chamber 24. FIG. 4 further shows, according to an alternative and preferred embodiment, the possible means for adjusting the fuel within the combustion chamber, which comprise a solenoid valve and a device integrating a float.

In a first embodiment solution, the fuel that drains from tank 22 to the combustion chamber 24 crosses a solenoid valve 42 associated to a level adjustment device 44 provided with a float 46. Said device 44 consists of a metal body comprising a conduit 48 which connects it on the one side to tank 22 and on the other side to the burner or combustion chamber 24; device 44 defines a measurement chamber 50 with vertical development, wherein float 46 is arranged. A rod 54 is vertically attached to float 46, made of a material having suitable chemical resistance features, and it moves integrally with the same float. Through such rod, which protrudes at the top from the level adjustment device 44, it is possible to show to the outside the indication of the minimum and maximum fuel levels desired within the combustion chamber 24. Such levels, moreover, are preferably subject to preventive calibration upon the manufacture or testing of appliance 10. Electronic level detectors of the known type (not shown) are installed on the top side of the measurement chamber 50, connected with the electronic control unit 40 that detects the minimum and maximum level signals of rod 54 connected to float 46. Also in this embodiment, the solenoid valve 42 is normally closed and this prevents the fuel passage between tank 22 and the combustion chamber 24. The solenoid valve 42 thus deactivated in advance also eliminates useless electrical energy wastes. Moreover, the fuel level within the combustion chamber 24 is always reduced to the minimum, with the consequence that no hazardous combustions may occur, not even in the event of overturning of appliance 10. In fact, the electronic control unit 40 receives the minimum level signal from the electronic detectors located within the measurement chamber 50 and accordingly sends a pulse to the solenoid valve 42 which temporarily opens up and lets the fuel drains from tank 22 to the measurement chamber 50 of device 44 and thereby to the combustion chamber 24. Conversely, when the predetermined maximum liquid level is reached within chamber 50, a new pulse is sent by the electronic control unit 40 to the solenoid valve 42, which instantly closes and interrupts the fuel passage.

In a second and alternative construction solution, the fuel that drains from tank 22 to the combustion chamber 24 crosses the solenoid valve 42 associated to a conduit. In the bottom portion of the combustion chamber 24 there are installed one or more metal level electrodes 90 of the known type, connected with the electronic control unit 40 which detects the minimum and maximum level signals. Such levels, moreover, are preferably subject to preventive calibration upon the manufacture or testing of appliance 10. Said metal detectors act as fuel level sensors based on the known physical principle of the electrical conductivity variation in the presence of elements having different values of the same: in particular, the voltage value detected by the electronic control unit 40 at the metal electrodes differs according to whether said electrode is in dry condition or wetted by the fuel. When the electronic control unit 40 receives the minimum level signal from the electronic detectors arranged within the combustion chamber 24, that is, when the minimum electrode or electrodes are not wetted by the fuel, it accordingly sends a pulse to the solenoid valve 42 which temporarily opens up and lets the fuel drain from tank 22 to the combustion chamber 24. Conversely, when the predetermined maximum level of liquid in the combustion chamber 24 is reached, that is, when the maximum electrode or electrodes are wetted by the fuel, a new pulse is sent by the electronic control unit 40 to the solenoid valve 42, which instantly closes up and interrupts the fuel passage. Also in this embodiment, the solenoid valve 42 is normally closed and this prevents the fuel passage between tank 22 and the combustion chamber 24. The solenoid valve 42 thus deactivated in advance also eliminates useless electrical energy wastes. Moreover, the fuel level present within the combustion chamber 24 is always reduced to the minimum, with the consequence that no hazardous combustions may occur, not even in the event of overturning of appliance 10.

According to a further advantageous feature of the invention, the filling of tank 22 is carried out by a quick coupling valve consisting of two complementary male and female parts, for example of the type known on the market as PLC series by Colder Products Company. A valve of this type allows coupling and uncoupling with the concurrent immediate opening/closing of the male and female elements without the need for flow intercepting taps. The two male-female elements, indicated with reference numerals 56 and 58 in FIG. 2 and partly in FIG. 3 are respectively attached to the fuel feeding tube coming out of a reservoir 60 and to a conduit 62 coming out of tank 22. The liquid present into reservoir 60, integrating the fuel reserve, falls into tank 22 by gravity, by pressure difference or by other known systems. Once the amount required to top up the fuel into tank 22 has been reached, the user separates the male-female components 56, 58 of the valve, interrupting the liquid flow without the occurrence of any fuel leaks.

A float 52 arranged within tank 22 is advantageously provided for causing the automatic closing of the feeding conduit 62 once the predetermined filling level into tank 22 has been reached. Said tank is provided with a venting valve 64 that facilitates the topping up operation. For safety purposes, it is envisaged that the loading or top up of tank 22 are only possible when the appliance is switched off and to this end, a microswitch of the known type is arranged at a door 66 that closes the inlet of conduit 62 and screens component 58 of said valve. Said microswitch is connected with the electronic control unit 40 which, receiving the electrical signal for opening door 66, causes the closing of separators 32, deactivating motor 36, thereby interrupting the combustion.

As an alternative or in addition, a tilting wall 23 interacting with a similar microswitch connected with said control unit may be provided for the same purpose on the access front of the filling valve.

The venting valve 64 also has the function of preventing the occurrence of overpressures within tank 22 resulting, for example, from high room temperatures. Moreover, said valve prevents the accidental leaking of fuel in the event of tilting or overturning of tank 22.

According to a further advantageous feature of the invention, the combustion chamber or burner 24 is made of a metal structure with multiple sectors connected to each other, which in particular define a top zone wherein the combustion takes place and a bottom zone wherein the combustible liquid is collected in the event of accidental overturning of the heating appliance.

In particular, as is seen in FIGS. 5, 6, 7 and more in detail in the latter, appliance 10 as a whole is advantageously supported by a base 68 wherealong tank 22, the combustion chamber 24, the level adjustment device 44 and the solenoid valve 42 develop. Adjacent to the combustion chamber 24, base 68 supports a block forming a cavity 74 which seats at least one electrical accumulator 76, apt to activate the movements of the various components managed by the card or electronic control unit 40, as well as the stepping motor 36 that controls the opening of separators 32, specifically shown in FIG. 5 in closed condition and in FIG. 6 in open condition. The combustion chamber 24 is placed between tank 22 and cavity 74 and comprises a cradle seat 78, extended longitudinally by the entire gap existing between the same tank 22 and cavity 74. Said cradle seat 78, which is apt to contain a limited amount of fuel constantly fed starting from tank 22 and from the level adjustment device 44 with float 46, is advantageously suspended relative to the lower plane defined by a portion of base 68 and in cooperation therewith and with respective and opposite side walls 80 extending vertically in longitudinal direction, it forms a cavity 82 at the bottom. The fuel present within the cradle seat 78 is collected into said latter in the event of an accidental forward or backward overturning of appliance 10, for example along the opposite longer sides. In particular, said fuel present within the cradle seat 78 outflows into cavity 82 through transfer slits or openings 70 that are made adjacent to said seat 78 by the entire perimeter of the combustion chamber and communicate with said cavity 82. In the event of an accidental and even partial overturning of appliance 10, an inclination or oscillation sensor (not shown) provides a signal to the control unit 40 for the immediate closing of separators 32, so that the fuel present within the cradle seat 78 is free from fuel and thus the flame blows out, as it happens in equal time or at a short distance for the part of fuel already fallen within cavity 82 through the transfer slits or openings 70. Under these possible emergency conditions the heating appliance 10 always ensures totally safe conditions, above all, safe from the possible outward spilling of fuel and related problems of flame propagation to the environment.

In the event of accidental and even partial overturning, the signal sent by the inclination sensor also determines the immediate interruption of the fuel feeding of tank 22 to the level adjustment device 44 that feeds the combustion chamber 44. It is advantageously envisaged that the maximum fuel amount present within tank 22 is such as to be distributed and be contained within the combustion chamber 24, levelling according to the principle of communicating vessels in the event of a failure of the dispensing system, thus preventing any outward leaks. Moreover, for operating safety purposes, the heating appliance of the present invention may be provided with a CO₂ detector interacting with the control unit 40 and with a timer apt to automatically switch off the same appliance when a given number of operating hours is reached. Moreover, the appliance may be provided with a container for diffusing fragrances in the environment, arranged adjacent the combustion chamber or in other suitable position.

The heating appliance of the present invention is advantageously made in the shape of a fireplace, as shown in FIGS. 1 and 8. According to a further advantageous feature of the invention, the side bands 12 are delimited by guiding section bars 72 and may therefore be extracted and replaced with other ones according to the user's needs or preferences. The same applies to the top crosswise panel 14. The side bands 12 and panel 14 may be made of metal or any other suitable material, with any surface decoration and/or finish. As can be noticed from the above, the advantages achieved by the invention are clear.

The heating appliance of the present invention ensures optimal safety levels since the tank fuel is constantly isolated from the combustion chamber and the periodical filling of the same tank is carried out in an easy, ergonomic manner and for higher safety, with blown out flame only.

Under this condition of non operating appliance, moreover, it is in any case impossible to directly pour the fuel into the burner since separators 32 are closed, to the advantage of safety.

The fuel dispensing into the burner, moreover, takes place with extreme accuracy and away from spilling or other types of hazards; even in the event of an accidental overturning of the appliance, the fuel does not come out of the burner or the tank as it is collected within the safety chamber.

A further advantage is the possibility of customising the appliance from the aesthetic point of view, thanks to the interchangeability of the side bands 12 and of the top panel 14. The same appliance may further be provided with wheels that facilitate the movement thereof. Although the invention has been described hereinbefore with particular reference to an embodiment thereof made by way of a non-limiting example, several changes and variations shall clearly appear to a man skilled in the art in the light of the above description. The present invention, therefore, is intended to include any changes and variations thereof falling within the spirit and the scope of protection of the following claims. 

1. A liquid hydrocarbon or bioethanol heating appliance (10), typically and non critically shaped as a movable fireplace with parallelepiped configuration, comprising a base 16, opposite side bands 12 with vertical development and a top connection panel (14) extended crosswise, wherein said base is provided with an opening (20) on the exposed top front, which can be screened with movable separators (32) and incorporates a tank (22) and a combustion chamber or burner (24) connected to said tank by a conduit (26), wherein a valve or solenoid valve (30) or (42) is provided with or combined to means that detect the fuel level in burner 24 and temporarily activate the same valves for allowing the passage of the amount of fuel required for restoring a given level in said burner, characterised in that it comprises one or more devices for adjusting the fuel level, which can be connected from a conduit (48) to a tank (22) and to the burner (24) and internally provided with a measurement chamber (50) with vertical development wherein a float (46) is arranged, coupled to a rod (54) that protrudes at the top from the same device, in said chamber (50) there being arranged electronic level detectors connected to the electronic control unit (40), as an alternative said device or devices for adjusting the fuel level can be seated directly inside the combustion chamber (24).
 2. The heating appliance according to claim 1, wherein said means suitable for detecting the fuel level consist of one or more probes (38), magnetic, electronic or similar detectors, arranged directly inside the combustion chamber (24), or within a valve (28) or in the device (44) arranged between the valve (42) and the combustion chamber (24), said detection means interacting with an electronic control unit (40) powered by one or more rechargeable batteries.
 3. The heating appliance according to claim 2, wherein the detection of fuel level is carried out by means of two or more metal electrodes (90) seated in the combustion chamber (24).
 4. The heating appliance according to claim 1, wherein the tank (22) is periodically fed by reservoir (60) through a quick coupling valve consisting of two complementary male/female elements (56-58) respectively fixed to the feeding tube of the fuel coming out of said reservoir and to a conduit (62) coming out of the tank (22).
 5. The heating appliance according to claim 4, wherein the tank (22) comprises a float (52) cooperating with the conduit (62), a venting valve (64) and a door (66) that closes the inlet of the same conduit (62) intercepting a microswitch connected to the electronic control unit (40) for causing the closure of said separators (32).
 6. The heating appliance according to claim 5, wherein the separators (32) are kept closed by helical springs (34) and are opened by the effect of an electrical motor (36) of the magnetic stepping type.
 7. The heating appliance according to claim 1, wherein it comprises a base (68) that supports the tank (22), the combustion chamber (24), the level adjustment device (44) and the solenoid valve (42), adjacent said combustion chamber (24) the base (68) supporting a block that forms a cavity (74) wherein there is arranged at least one electrical accumulator (76) for powering and moving the components connected to the electronic control unit (40) and the electrical motor (36) for opening the separators (32).
 8. The heating appliance according to claim 1, wherein the combustion chamber (24) is arranged between the tank (22) and the cavity (74) and comprises a cradle seat (78) extended longitudinally and hanging relative to the lower plane defined by the base (68).
 9. The heating appliance according to claim 8, wherein said cradle seat (78) is delimited by opposite side walls (80) with vertical development which, combined with a part of the base (68), form a cavity (82) underneath the same cradle.
 10. The heating appliance according to claim 9, wherein adjacent the cradle seat (78) there are obtained transfer slits or openings (70) communicating with the cavity (82), said slits extending externally along the combustion chamber (24) wherein said cradle seat is formed.
 11. The appliance according to claim 1, wherein it comprises a CO₂ detector interacting with the electronic control unit (40).
 12. The appliance according to claim 1, characterised in that it comprises a timer that causes the switching off thereof when a predetermined number of operating hours is reached. 